Title: DNA and RNA Grade Level:10th Course: Biology Lesson Overview
This lesson will introduce the students to DNA and RNA. Students will learn that cells store and use information to guide their functions and that the genetic information stored in DNA is used to direct the synthesis of the thousands of proteins that each cell requires.
In all organisms, the instructions for specifying the characteristics of the organism are carried in DNA, a large polymer formed from subunits of four kinds (A,G,C,and T). The chemical and structural properties of DNA explain how the genetic information that underlies heredity is both encoded in genes (as a string of molecular "letters") and replicated (by a templating mechanism).
We will explore the flow of genetic information from DNA-RNA-PROTEIN. Students will become familiar with the function of RNA and how proteins get translated. We will also cover the three main types of RNA and their functions: mRNA, rRNA, and tRNA. Students will also learn how DNA affects our phenotype. That is, how DNA encodes for the proteins that makes us look the way we do.
Learning Performances
Students should be able to:
· specifically identify the location of DNA in the cell
· describe the location of RNA translation
· explain how DNA is comprised of genes
· explain how DNA is a nucleic acid, one of the four macromolecules
· identify the location f chromosomes in the cell and explain what chromosomes consist of
· explain why RNA is the principal molecule carrying out the instructions of DNA
· apply their knowledge about mRNA, rRNA, and tRNA to explain the overall process of transcription and translation
Links to Standards or Benchmarks R.I K-12 Grade Span Expectations in Science. Life Science LS-1 (9-11)-2 Students demonstrate an understanding of the molecular basis for heredity by... 2c describing how DNA contains the code for the production of specific proteins.
Materials Needed
Materials for me:
· Website for animations of DNA and RNA
· PowerPoint
· Model of a cell (to be assembled by each group from clay or from twine and tape)
· Whiteboard
· pipe cleaners and beads (to be used as DNA and RNA backbones and nucleotides)
· wiffle ball (to be used as rRNA)
· multicolored pegs (to represent amino acids)
Time Required
Two 90min block periods
Instructional Sequence
Introducing the lesson
I will begin by asking what their prior knowledge of DNA and RNA is. I will ask several questions in trying to assess their current level of knowledge on this topic. To motivate and capture students' attention I will look around the room and then point out a few observable genetic traits about the students. For example, I will say something like "look, Janelle has a "widow's peak" on her hairline" (this is a genetic trait and it's expressed as a small triangular shape of hair on a person's forehead). Another example would be to ask students if anyone can roll their tongue or if anyone knows someone who has different colored eyes. I then would say that my grandmother had different colored eyes and explain to the class that it was influenced by her genetics.
To frame this lesson, I will ask the students the following question: "Have you ever wondered why some genetic traits seem to run in the families (ex: dimples, freckles, baldness) and some don't? (ex:double jointedness, widow's peak) I would then tell the students that in this lesson we will be learning about genetics and the process of our genes being expresses the way they are in us. I will also tell them that by the end of the lesson we will revisit this question and attempt to answer it.
To establish a meaningful purpose for this lesson and the acitivities to be performed, I would explain to the students that our genetic code (DNA) is extremely important and influences every single one of us and encodes for the proteins that really make us look the way we do. I then will give the students a quick overview of the lesson. I will tell them that we will be stimulating the process of genetic flow from DNA-RNA-PROTEIN. I will introduce them to the materials that we will be using and I will explain which cellular molecule or structure each of the materials represents. I then will ask the students to get in groups and have them go to their work stations (which I have previously set up for them).
Instructional Activities
In this lesson, students will use common items to help demonstrate the process of transcription, translation, and synthesis of proteins. This hands-on approach can be used for the students to retain this information that is often abstract and difficult to understand.
I will begin the lesson by representing the cell and the nucleus pictorially. To do this, I will ask the students in their groups to use clay or twine and type. This will give the students a spatial understanding about where the steps of each process from DNA-RNA-PROTEIN take place.
Next I will introduce the students to the three main types of RNA (mRNA, rRNA, and tRNA). We will review the structure of DNA and the pairing of nucleotides (A-T, G-C) as well as the structure of RNA and the pairing of RNA nucleotides (A-U, G-C).
The students will have already learned about the three main types of RNAs (mRNA, rRNA, and tRNA). I will reintroduce them to these again in more depth. In the past lessons, students have been introduced to the basic components of genetic pathway and they are familiar with some of the functions of the transcriptional and translational processes.
I will inform the students that the rationale for this activity is to learn about the essential steps about how genetic information follows the DNA-RNA-PROTEIN pathway. I will explain to them that knowing the function and location of each of the three main types of RNAs is essential to our understanding of the whole genetic pathway process.
I will not be passing any extra materials out because the students will be sitting at their work stations and they will already have all the needed materials in front of them. By this point in the lesson, the students will create their model of a cell displaying the nucleus and the cytoplasm. They will also write down mRNA, rRNA, and tRNA and include each RNA's function. By following their worksheet, they will also write down the functions of DNA and RNA and their respective nucleotides and the pairing of their nucleotides.
I will now introduce the students to the materials that they will be using, the pipe cleaners and the beads. Pipe cleaners will represent the backbone of DNA and RNA molecules. DNA will be a couple of white pipe cleaners and RNA will be a couple of green pipe cleaners. The beads will have letters printed on them. Each team of students will get beads with the letters "A", "T", "G", and "C" printed on them. Students will be instructed to simulate a double stranded molecule of DNA by using the pipe cleaners and the beads.
To connect the model with the idea of the molecules involved, students will be explained to that the pipe cleaners will represent the backbones of RNA and DNA and that the beads will represent the individual nucleotides. I will also inform the students that by physically manipulating the materials and creating the RNA and DNA molecules, they will hopefully better understand the process of assemblying these molecules and the importance of base-pairing in the nucleotides.
Next I will give directions so that the students will create one strand first and then pair it up with the corresponding strand based on the information of the first strand. Students then place the DNA molecule in the nucleus of their cell. The DNA molecule is confined to the nucleus and cannot leave the nucleus.
I will demonstrate this process for the students in order to provide them with a concrete visual representation. By this point in the lesson, the students will follow their worksheet and write down what the pipe cleaners and the beads are demonstrating in this lesson. They will also make a note in their worksheet about the location of DNA and whether or not DNA can be relocated around the cell. In addition, they will create the first strand of a DNA molecule and pair it up with a corresponding strand based on the information on the first strand. They will also write down the paired nucleotide sequence on their worksheet.
To guide the students in each step of the sequenced worksheet, I will ask them to follow their worksheet in each step of the activity. This is important to keep their thoughts organized and to also provide them with an opportunity to ask me questions in case they don't understand something.
To promote students' thinking, I will ask them how the genetic information could be moved out of the nucleus if it's contained in the DNA and the DNA cannot leave the nucleus. We will have a short discussion in trying to come up with an answer to this problem. As students will be discussing this issue, they will realize that the nucleus has to have some perforations in order to allow anything out of the nucleus. At this point, we will talk about the nuclear pores and their function.
We will then talk about transcription, the first big step in DNA-RNA-PROTEIN. I will explain to the students how DNA is like a blueprint which holds our genetic information and how it has to be re-written into RNA to be translated into proteins.
I will ask the students at this point to simulate transcription by using a green pipe cleaner (representing RNA backbone) and the corresponding nucleotides for RNA (beads with letters printed on them). Students will unzip and work with the DNA strand to encode the RNA (this new molecule will be the messenger RNA that will be sent to the cytoplasm to start being encoded into proteins).
Once mRNA is assembled, I will ask the students to take it out of the nucleus (via the nuclear pores) and move it into the cytoplasm to be translated. By this point in the lesson, by following their worksheet, the students will write down the function of nuclear pores. They will also write down the description of transcription. In addition, students will indicate on their worksheet a sequence of DNA and transcribe it into an mRNA (ex: DNA - A T C G A C G T A will be transcribed into
RNA - U A G C U G C A U)
Once mRNA is assembled, students will take it out of the nucleus (via the nuclear pores; good point in the lesson to revisit the function of nuclear pores) and move the mRNA into the cytoplasm.
Once the beads and the pipe cleaner are in the cytoplasm, students will be instructed to locate the ribosomes. To represent the ribosomes, students will use wiffle balls cut in half. Each half of the wiffle ball will represent the sub-units of a ribosome. It is also at this point where we will have a quick review of ribosomes and their function in the cell. I will emphasize to the students the chemical composition of the ribosomes, and point out that they are one of the other forms of RNA, termed rRNA (ribosomal RNA). The mRNA is then moved to the wiffle ball (rRNA), where it will wait for the next step: translation.
At this time, we will quickly review the structure and function of tRNA (transfer RNA). After a short class discussion, I will ask the students to bend orange pipe cleaners to stimulate the shape of tRNA. I will also give them pegs (multicolored pegs that will connect easily). These pegs will simulate amino acids. The students will be attaching the pegs to the end of the pipe cleaner representing tRNA. By this point in the lesson, students will indicate on their worksheets the function and location of ribosomes. They will also describe what translation is and will indicate the location of translation in the cell. In addition, students will write down the function of tRNA and they will draw a simple diagram of a tRNA containing amino acids (which are the anti-codons).
At this point, we will discuss translation again and I will stress the importance of codons and anti-codons in the cell. I will explain how the protein assemblying process works. The translation discussion will be followed by students' simulation of this process, in which tRNA gets together with the mRNA in the ribosome (rRNA). The end result: amino acids get assembled into proteins!
I will say to the students that this activity is a great representation of the translation process. By manipulating the individual molecules involved in this process, they are gaining a greater visual understanding of this concept.
At the end of this activity, I would like the students to write down on their worksheets a sequence of three sets of assembled codons. Then they would use a protein table (which I will provide to them) to locate these assembled sequences and write down the names of the proteins that they have assembled. This could also be a wonderful extension and an interesting conversation to desribe what the proteins that they assembled are responsible for in our bodies.
Concluding the Lesson
To reinforce the purpose of this lesson, we will have a whole class discussion upon completing all the activities. I would briefly state the main learing goals for this lesson and describe the flow of genetic information from DNA-RNA-PROTEINS. I would then provide several examples of what might happen if the DNA gets transcribed incorrectly. To relate this information to student lives and issues in society, I would explain to the students that upon incorrect transcription of DNA, mutations would result. Specifiacally, I would mention some common mutations, like Down Syndrome and Sickle Cell Anemia.
To bring this whole lesson together, I would perhaps refer again to "Janelle's "widow's peak" " or someone's ability to "roll in their tongue" and then explain to them how the certain arrangement of nucleotides that they were using (represented by the beads) are responsible for these genetic traits.
In conclusion, I would state the main idea that DNA stores our genetic information and that it's located in the nucleus. Also, RNA is needed as an messenger to deliver the genetic information out of the nucleus into the cytoplasm to be translated into proteins in the ribosomes with the help of rRNA and tRNA.
Each of the activities that the students will be performing are strongly related to the learning goals. These activities are targeted for multiple intelligences. For example, students who are visual learners will benefit by the animations shown on the web in the beginning of the class as well as learning on their cell model and having visual structures of all the molecules. Students who are interpersonal learners will also benefit greatly from this lesson because they will be working within a group setting and there will be many opportunities for discussion. Also, kinesthetic learners will benefit because they can use their fine motor skills to manipulate the models that they are building throuhout the lesson. Students of all the various intelligences should be able to use their skills and benefit from this lesson. Lastly, after each activity and discussion, students will fill in their worksheet as we go along in the lesson. This should reinforce the material for everyone and provide an opportunity to ask questions and clear out any misunderstandings.
Assessing Student Understanding
I will determine if the students have met their learning performances through formative and summative assessments. The formative assessment will be the worksheet that I will provide to the students. Throughout the lesson, students will be asked to write down/draw diagrams of the material that we will be covering in the lesson. I will circulate around the room and assess students' responses on the worksheet. This will give me a better understanding of their comprehension as well as provide them an opportunity to make sure that they are understanding the material and that they are writing down correct information.
Summative assessment will be an end of the chapter test. The test will include a few multiple choice questions, a few short answer questions, and three essays (from which the students will have to choose ONE to write about). The multiple choice and short answer questions will be targeted to assess their understanding of the definitions and functions of the covered molecules. For example: "what is the principal function of RNA?" or "which molecules are needed to assist in the protein assembly?" The essay questions however, will be more complex and will focus on deeper understanding and students' ability to apply higher order thinking skills. For example, I might ask the following essay question: "Explain the flow of genetic information in an organism. Specifically, explain how genetic information follows the DNA-RNA-PROTEIN pathway. Be sure to explain transcription and translation and all the important molecules and their functions involved in the processes."
I will also assign homework for the students so they could better understand this complicated topic. For their homework, I will ask them to draw a diagram of a cell and then indicate the location of transcription and translation in that cell. In addition, they would need to draw two more diagrams, one of them representing transcription and the other translation (diagram needs to include all the necessary molecules involved).
Finally, to truly assess students' knowledge of this topic, I would revisit the initial framing question of the lesson: "Have you ever wondered why some genetic traits seem to run in the families (ex: dimples, freckles, baldness) and some don't? (ex:double jointedness, widow's peak). We would then have a class discussion and reflect on everything we learned about genetics and see if we could come up with an answer to this question.
Cautions
As far as the lesson materials go, there really are not any dangerous or hazardous components associated with the activities that the students will be performing. This is a nice, entertaining, and low tech approach to the central dogma of biology.
The only precaution that I would take, is extra care and sensitivity when talking about possible mutations (ex: Down Syndrome). I wouldn't want to offend anybody who might have genetic defects or might have family/friends with genetic defects. I will use "person first" language when covering some of the potential genetic diseases.
Sources
The main idea for this lesson really just came from my own experience in cellular biology courses. I have always found cell biology interesting and I thought that the central dogma of biology (the sequential transfer of information in a cell) would be an important concept to teach in a high school class.
I did do some research online for classroom activities on this topic and found a great lesson on the National Association of Biology Teachers. I adapted the cleaning pipes and beads activity from that lesson. Source: A hands-on Approach to Teaching the Central Dogma of Biology. Retrieved October 27, 2007, from National Association of Biology Teachers Web site: http://www.nabt.org/sites/S1/File/pdf/DNA_Day_cdogma.pdf
Since there will be students with multiple intelligences in the classroom, this lesson is a great visual representation of a rather complicated topic. The set-up of this lesson will address all the three modalities of how students learn: auditory, visual, and kinesthetic. The auditory learners will benefit from the class discussion and from me explaining the concepts to the students and by revisiting our previous knowledge of this topic.
The visual learners will benefit greatly from the visual representation of the cell and all of its components.
The kinesthetic learners will be provided numerous opportunities throughout the activities to manipulate molecules in order to assemble the processeses of transcription and translation.
Also, since I will begin this lesson with an essential framing question, students will have a specific goal to work towards to - the answer to that question. This gives them focus and purpose for doing the activities and learning the material.
In addition, I will be making many personal and relevant references about the importance of genetics (ex: phenotypic traits that are influenced by our genetics like different colored eyes, freckles, dimples, widow's peak etc). This all will hopefully engage the students and create more of a personal connection between them and the topic of the lesson.
Grade Level:10th
Course: Biology
Lesson Overview
This lesson will introduce the students to DNA and RNA. Students will learn that cells store and use information to guide their functions and that the genetic information stored in DNA is used to direct the synthesis of the thousands of proteins that each cell requires.
In all organisms, the instructions for specifying the characteristics of the organism are carried in DNA, a large polymer formed from subunits of four kinds (A,G,C,and T). The chemical and structural properties of DNA explain how the genetic information that underlies heredity is both encoded in genes (as a string of molecular "letters") and replicated (by a templating mechanism).
We will explore the flow of genetic information from DNA-RNA-PROTEIN. Students will become familiar with the function of RNA and how proteins get translated. We will also cover the three main types of RNA and their functions: mRNA, rRNA, and tRNA. Students will also learn how DNA affects our phenotype. That is, how DNA encodes for the proteins that makes us look the way we do.
Learning Performances
Students should be able to:
· specifically identify the location of DNA in the cell
· describe the location of RNA translation
· explain how DNA is comprised of genes
· explain how DNA is a nucleic acid, one of the four macromolecules
· identify the location f chromosomes in the cell and explain what chromosomes consist of
· explain why RNA is the principal molecule carrying out the instructions of DNA
· apply their knowledge about mRNA, rRNA, and tRNA to explain the overall process of transcription and translation
Links to Standards or Benchmarks
R.I K-12 Grade Span Expectations in Science. Life Science
LS-1 (9-11)-2 Students demonstrate an understanding of the molecular basis for heredity by...
2c describing how DNA contains the code for the production of specific proteins.
Materials Needed
Materials for me:
· Website for animations of DNA and RNA
· PowerPoint
· Model of a cell (to be assembled by each group from clay or from twine and tape)
· Whiteboard
· pipe cleaners and beads (to be used as DNA and RNA backbones and nucleotides)
· wiffle ball (to be used as rRNA)
· multicolored pegs (to represent amino acids)
Time Required
Two 90min block periods
Instructional Sequence
Introducing the lesson
I will begin by asking what their prior knowledge of DNA and RNA is. I will ask several questions in trying to assess their current level of knowledge on this topic. To motivate and capture students' attention I will look around the room and then point out a few observable genetic traits about the students. For example, I will say something like "look, Janelle has a "widow's peak" on her hairline" (this is a genetic trait and it's expressed as a small triangular shape of hair on a person's forehead). Another example would be to ask students if anyone can roll their tongue or if anyone knows someone who has different colored eyes. I then would say that my grandmother had different colored eyes and explain to the class that it was influenced by her genetics.
To frame this lesson, I will ask the students the following question: "Have you ever wondered why some genetic traits seem to run in the families (ex: dimples, freckles, baldness) and some don't? (ex:double jointedness, widow's peak) I would then tell the students that in this lesson we will be learning about genetics and the process of our genes being expresses the way they are in us. I will also tell them that by the end of the lesson we will revisit this question and attempt to answer it.
To establish a meaningful purpose for this lesson and the acitivities to be performed, I would explain to the students that our genetic code (DNA) is extremely important and influences every single one of us and encodes for the proteins that really make us look the way we do. I then will give the students a quick overview of the lesson. I will tell them that we will be stimulating the process of genetic flow from DNA-RNA-PROTEIN. I will introduce them to the materials that we will be using and I will explain which cellular molecule or structure each of the materials represents. I then will ask the students to get in groups and have them go to their work stations (which I have previously set up for them).
Instructional Activities
In this lesson, students will use common items to help demonstrate the process of transcription, translation, and synthesis of proteins. This hands-on approach can be used for the students to retain this information that is often abstract and difficult to understand.
I will begin the lesson by representing the cell and the nucleus pictorially. To do this, I will ask the students in their groups to use clay or twine and type. This will give the students a spatial understanding about where the steps of each process from DNA-RNA-PROTEIN take place.
Next I will introduce the students to the three main types of RNA (mRNA, rRNA, and tRNA). We will review the structure of DNA and the pairing of nucleotides (A-T, G-C) as well as the structure of RNA and the pairing of RNA nucleotides (A-U, G-C).
The students will have already learned about the three main types of RNAs (mRNA, rRNA, and tRNA). I will reintroduce them to these again in more depth. In the past lessons, students have been introduced to the basic components of genetic pathway and they are familiar with some of the functions of the transcriptional and translational processes.
I will inform the students that the rationale for this activity is to learn about the essential steps about how genetic information follows the DNA-RNA-PROTEIN pathway. I will explain to them that knowing the function and location of each of the three main types of RNAs is essential to our understanding of the whole genetic pathway process.
I will not be passing any extra materials out because the students will be sitting at their work stations and they will already have all the needed materials in front of them.
By this point in the lesson, the students will create their model of a cell displaying the nucleus and the cytoplasm. They will also write down mRNA, rRNA, and tRNA and include each RNA's function. By following their worksheet, they will also write down the functions of DNA and RNA and their respective nucleotides and the pairing of their nucleotides.
I will now introduce the students to the materials that they will be using, the pipe cleaners and the beads. Pipe cleaners will represent the backbone of DNA and RNA molecules. DNA will be a couple of white pipe cleaners and RNA will be a couple of green pipe cleaners. The beads will have letters printed on them. Each team of students will get beads with the letters "A", "T", "G", and "C" printed on them. Students will be instructed to simulate a double stranded molecule of DNA by using the pipe cleaners and the beads.
To connect the model with the idea of the molecules involved, students will be explained to that the pipe cleaners will represent the backbones of RNA and DNA and that the beads will represent the individual nucleotides. I will also inform the students that by physically manipulating the materials and creating the RNA and DNA molecules, they will hopefully better understand the process of assemblying these molecules and the importance of base-pairing in the nucleotides.
Next I will give directions so that the students will create one strand first and then pair it up with the corresponding strand based on the information of the first strand. Students then place the DNA molecule in the nucleus of their cell. The DNA molecule is confined to the nucleus and cannot leave the nucleus.
I will demonstrate this process for the students in order to provide them with a concrete visual representation.
By this point in the lesson, the students will follow their worksheet and write down what the pipe cleaners and the beads are demonstrating in this lesson. They will also make a note in their worksheet about the location of DNA and whether or not DNA can be relocated around the cell. In addition, they will create the first strand of a DNA molecule and pair it up with a corresponding strand based on the information on the first strand. They will also write down the paired nucleotide sequence on their worksheet.
To guide the students in each step of the sequenced worksheet, I will ask them to follow their worksheet in each step of the activity. This is important to keep their thoughts organized and to also provide them with an opportunity to ask me questions in case they don't understand something.
To promote students' thinking, I will ask them how the genetic information could be moved out of the nucleus if it's contained in the DNA and the DNA cannot leave the nucleus. We will have a short discussion in trying to come up with an answer to this problem. As students will be discussing this issue, they will realize that the nucleus has to have some perforations in order to allow anything out of the nucleus. At this point, we will talk about the nuclear pores and their function.
We will then talk about transcription, the first big step in DNA-RNA-PROTEIN. I will explain to the students how DNA is like a blueprint which holds our genetic information and how it has to be re-written into RNA to be translated into proteins.
I will ask the students at this point to simulate transcription by using a green pipe cleaner (representing RNA backbone) and the corresponding nucleotides for RNA (beads with letters printed on them). Students will unzip and work with the DNA strand to encode the RNA (this new molecule will be the messenger RNA that will be sent to the cytoplasm to start being encoded into proteins).
Once mRNA is assembled, I will ask the students to take it out of the nucleus (via the nuclear pores) and move it into the cytoplasm to be translated.
By this point in the lesson, by following their worksheet, the students will write down the function of nuclear pores. They will also write down the description of transcription. In addition, students will indicate on their worksheet a sequence of DNA and transcribe it into an mRNA (ex: DNA - A T C G A C G T A will be transcribed into
RNA - U A G C U G C A U)
Once mRNA is assembled, students will take it out of the nucleus (via the nuclear pores; good point in the lesson to revisit the function of nuclear pores) and move the mRNA into the cytoplasm.
Once the beads and the pipe cleaner are in the cytoplasm, students will be instructed to locate the ribosomes. To represent the ribosomes, students will use wiffle balls cut in half. Each half of the wiffle ball will represent the sub-units of a ribosome. It is also at this point where we will have a quick review of ribosomes and their function in the cell. I will emphasize to the students the chemical composition of the ribosomes, and point out that they are one of the other forms of RNA, termed rRNA (ribosomal RNA). The mRNA is then moved to the wiffle ball (rRNA), where it will wait for the next step: translation.
At this time, we will quickly review the structure and function of tRNA (transfer RNA). After a short class discussion, I will ask the students to bend orange pipe cleaners to stimulate the shape of tRNA. I will also give them pegs (multicolored pegs that will connect easily). These pegs will simulate amino acids. The students will be attaching the pegs to the end of the pipe cleaner representing tRNA.
By this point in the lesson, students will indicate on their worksheets the function and location of ribosomes. They will also describe what translation is and will indicate the location of translation in the cell. In addition, students will write down the function of tRNA and they will draw a simple diagram of a tRNA containing amino acids (which are the anti-codons).
At this point, we will discuss translation again and I will stress the importance of codons and anti-codons in the cell. I will explain how the protein assemblying process works. The translation discussion will be followed by students' simulation of this process, in which tRNA gets together with the mRNA in the ribosome (rRNA). The end result: amino acids get assembled into proteins!
I will say to the students that this activity is a great representation of the translation process. By manipulating the individual molecules involved in this process, they are gaining a greater visual understanding of this concept.
At the end of this activity, I would like the students to write down on their worksheets a sequence of three sets of assembled codons. Then they would use a protein table (which I will provide to them) to locate these assembled sequences and write down the names of the proteins that they have assembled. This could also be a wonderful extension and an interesting conversation to desribe what the proteins that they assembled are responsible for in our bodies.
Concluding the Lesson
To reinforce the purpose of this lesson, we will have a whole class discussion upon completing all the activities. I would briefly state the main learing goals for this lesson and describe the flow of genetic information from DNA-RNA-PROTEINS. I would then provide several examples of what might happen if the DNA gets transcribed incorrectly. To relate this information to student lives and issues in society, I would explain to the students that upon incorrect transcription of DNA, mutations would result. Specifiacally, I would mention some common mutations, like Down Syndrome and Sickle Cell Anemia.
To bring this whole lesson together, I would perhaps refer again to "Janelle's "widow's peak" " or someone's ability to "roll in their tongue" and then explain to them how the certain arrangement of nucleotides that they were using (represented by the beads) are responsible for these genetic traits.
In conclusion, I would state the main idea that DNA stores our genetic information and that it's located in the nucleus. Also, RNA is needed as an messenger to deliver the genetic information out of the nucleus into the cytoplasm to be translated into proteins in the ribosomes with the help of rRNA and tRNA.
Each of the activities that the students will be performing are strongly related to the learning goals. These activities are targeted for multiple intelligences. For example, students who are visual learners will benefit by the animations shown on the web in the beginning of the class as well as learning on their cell model and having visual structures of all the molecules. Students who are interpersonal learners will also benefit greatly from this lesson because they will be working within a group setting and there will be many opportunities for discussion. Also, kinesthetic learners will benefit because they can use their fine motor skills to manipulate the models that they are building throuhout the lesson. Students of all the various intelligences should be able to use their skills and benefit from this lesson. Lastly, after each activity and discussion, students will fill in their worksheet as we go along in the lesson. This should reinforce the material for everyone and provide an opportunity to ask questions and clear out any misunderstandings.
Assessing Student Understanding
I will determine if the students have met their learning performances through formative and summative assessments. The formative assessment will be the worksheet that I will provide to the students. Throughout the lesson, students will be asked to write down/draw diagrams of the material that we will be covering in the lesson. I will circulate around the room and assess students' responses on the worksheet. This will give me a better understanding of their comprehension as well as provide them an opportunity to make sure that they are understanding the material and that they are writing down correct information.
Summative assessment will be an end of the chapter test. The test will include a few multiple choice questions, a few short answer questions, and three essays (from which the students will have to choose ONE to write about). The multiple choice and short answer questions will be targeted to assess their understanding of the definitions and functions of the covered molecules. For example: "what is the principal function of RNA?" or "which molecules are needed to assist in the protein assembly?" The essay questions however, will be more complex and will focus on deeper understanding and students' ability to apply higher order thinking skills. For example, I might ask the following essay question: "Explain the flow of genetic information in an organism. Specifically, explain how genetic information follows the DNA-RNA-PROTEIN pathway. Be sure to explain transcription and translation and all the important molecules and their functions involved in the processes."
I will also assign homework for the students so they could better understand this complicated topic. For their homework, I will ask them to draw a diagram of a cell and then indicate the location of transcription and translation in that cell. In addition, they would need to draw two more diagrams, one of them representing transcription and the other translation (diagram needs to include all the necessary molecules involved).
Finally, to truly assess students' knowledge of this topic, I would revisit the initial framing question of the lesson: "Have you ever wondered why some genetic traits seem to run in the families (ex: dimples, freckles, baldness) and some don't? (ex:double jointedness, widow's peak). We would then have a class discussion and reflect on everything we learned about genetics and see if we could come up with an answer to this question.
Cautions
As far as the lesson materials go, there really are not any dangerous or hazardous components associated with the activities that the students will be performing. This is a nice, entertaining, and low tech approach to the central dogma of biology.
The only precaution that I would take, is extra care and sensitivity when talking about possible mutations (ex: Down Syndrome). I wouldn't want to offend anybody who might have genetic defects or might have family/friends with genetic defects. I will use "person first" language when covering some of the potential genetic diseases.
Sources
The main idea for this lesson really just came from my own experience in cellular biology courses. I have always found cell biology interesting and I thought that the central dogma of biology (the sequential transfer of information in a cell) would be an important concept to teach in a high school class.
I did do some research online for classroom activities on this topic and found a great lesson on the National Association of Biology Teachers. I adapted the cleaning pipes and beads activity from that lesson. Source: A hands-on Approach to Teaching the Central Dogma of Biology. Retrieved October 27, 2007, from National Association of Biology Teachers Web site: http://www.nabt.org/sites/S1/File/pdf/DNA_Day_cdogma.pdf
Teaching Resources
Rationale
Since there will be students with multiple intelligences in the classroom, this lesson is a great visual representation of a rather complicated topic. The set-up of this lesson will address all the three modalities of how students learn: auditory, visual, and kinesthetic. The auditory learners will benefit from the class discussion and from me explaining the concepts to the students and by revisiting our previous knowledge of this topic.
The visual learners will benefit greatly from the visual representation of the cell and all of its components.
The kinesthetic learners will be provided numerous opportunities throughout the activities to manipulate molecules in order to assemble the processeses of transcription and translation.
Also, since I will begin this lesson with an essential framing question, students will have a specific goal to work towards to - the answer to that question. This gives them focus and purpose for doing the activities and learning the material.
In addition, I will be making many personal and relevant references about the importance of genetics (ex: phenotypic traits that are influenced by our genetics like different colored eyes, freckles, dimples, widow's peak etc). This all will hopefully engage the students and create more of a personal connection between them and the topic of the lesson.
DEMO LP EVAL KERLY BY JAY